Primality proof for n = 3678217:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=153259.html>153259 is prime.</a>
<br>b^((n-1)/153259)-1 mod n = 2064347, which is a unit, inverse 52404.
<p>(153259) divides n-1.
<p>(153259)^2 > n.
<p>n is prime by Pocklington's theorem.